This project is focused on the study of the endomembranes systems (the endoplasmic reticulum and peripheric vacuoles) of Giardia, a very primitive unicellular eukaryote. This study is part of a larger project on the endocytotic and intracellular trafficking and protein sorting processes in this organism. There is also interest in the study of the motor system of Giardia because by videomicroscopy we could see that the flagella moves as well as cell body. For this purpose we have collaborated with the NCMIR. Tomographic reconstructions have been performed on Giardia at the NCMIR in order to see the relationship between the endoplasmic reticulum and peripheric vacuoles. Several tomographc reconstructions were obtained while Dr. Attias visited the NCMIR in December, 1996. We have been tracing the outlines of the endoplasmic reticulum and the peripheric vacuoles using XVOXTRACE and have sent the completed reconstructions to Dr. Attias.